COLUMBUS, Ohio -- The symposium on Justice Ruth Bader Ginsburg's life on and before the Supreme Court had all the trappings of a grand finale: laudatory tributes, scholarly evaluations of her jurisprudence, a running theme about her love of opera and her unfulfilled desire to be a great diva.

Conspicuously missing was any mention of an exit from the stage.

If anything, Ginsburg's appearance at Ohio State University's Moritz College of Law -- and at a host of other events since the 76-year-old justice had surgery in February to remove a cancerous pancreatic tumor -- seemed intended to send a contrary message.

She hasn't missed a session of the court, either in recuperation from surgery or because of the cautionary chemotherapy started in March. She has issued more opinions since then than any of the other justices, save one, and has been an active and persistent questioner in oral arguments.

She went to President Obama's address to Congress less than three weeks after surgery to show she was "alive and well"; dragged her reclusive colleague David H. Souter to the opera; traveled to Boston to address law students; and last week presided over a mock trial based on "Twelfth Night" at the Washington Shakespeare Theater.

In a video tribute shown at Friday's day-long symposium, Chief Justice John G. Roberts Jr. offered "my warm congratulations on the occasion of your reaching the midpoint of your tenure." He said Ginsburg -- who is celebrating 15 years on the high court -- has "earned acclaim for your work ethic, intellectual rigor, precision with words and total disregard for the normal day-night work schedule adhered to by everyone else since the beginning of recorded history."

As the symposium focused on Ginsburg's role on the court -- her fierce defense of women's rights, commitment to gender equality, the symbolic effect of being the only female justice and her reputation as a dependable if not crusading member of the court's liberal bloc were the broad themes -- the background was what comes next.

The question of whether and when Obama might have his chance to make a mark on the court consumes those who watch it most closely. The longest-serving justice, John Paul Stevens, turns 89 within days but shows no sign of departing. Those who monitor the court are watching to see if Souter, 69, starts hiring clerks for next term or decides it is time to return to his beloved New Hampshire.

Since both men, along with Ginsburg, are part of the four-member liberal wing of the court, Obama's choice of a replacement would not change the balance of a court that regularly finds itself in an ideological tug-of-war. Roberts and Justices Antonin Scalia, Clarence Thomas and Samuel A. Alito Jr. are consistent conservative voters, with Justice Anthony M. Kennedy often casting the deciding vote.

Those divisions will likely be on display later this month, as the court completes its oral arguments for the year. Among the items on the agenda: the continued need for a key section of the Voting Rights Act, the ability of white job-seekers to sue governments for discrimination and the privacy rights of students.

Because of her consistency, Ginsburg is not likely to cast the decisive vote in any of the cases. Her time on the court is marked by meticulous detail and movement of the law in stages; her specialty is civil procedure. The symposium's keynote speaker, Peter J. Rubin, who founded the liberal American Constitution Society and is now a Massachusetts judge, said Ginsburg has "altered the course of American constitutional law." The case he chose to illustrate her judicial approach was one about the timing of bankruptcy filings.

Ginsburg, unlike some of her colleagues, often makes her case in public speeches. And, when she thinks her colleagues have misinterpreted a statute, she writes a dissent that on Friday she called a "red flag," essentially asking Congress to take action.

Her dissent in the court's 2007 decision that threw out an Alabama tire company manager's suit alleging discriminatory pay made Lilly Ledbetter a heroine on the left and led Congress to change the law, presenting Obama with his first major bill to sign. House Speaker Nancy Pelosi (D-Calif.) acknowledged in a letter read at the symposium another message from Ginsburg, sent in a dissent last month in a case about the Voting Rights Act.

On stage for a question-and-answer session conducted by friendly law professors, Ginsburg was a tiny figure in black with bold jewelry and a luxurious stole. She moved slowly, but her voice was strong and her words precise. She made no mention, as she had in Boston, that an opening on the court could come "soon." Nor did she talk about her own plans, which she has indicated in the past include at least another five years on the court.

Instead, she stuck to familiar topics: a defense of looking to the holdings of foreign courts to inform the Supreme Court's decisions; her view that the "court never leads" in promoting social change but works in concert with other branches of government; her work as a lawyer in promoting gender equality; and her frustration at being the court's lone female since the first, Sandra Day O'Connor, left the court in 2006.

"Now, there I am all alone, and it doesn't look right," Ginsburg said. She said she watches the number of women at each session of the Supreme Court bar, notices that four of the nine members of Canada's Supreme Court are women, including the chief justice, and sees the female reporters who cover the court.

"It's lonely for me. Not that I don't love all my colleagues. I do," Ginsburg said.

She said she believes the controversy over whether the court should look to the experiences of a foreign court "is a passing phase."

"I frankly don't understand all the brouhaha lately in Congress and even from some of my colleagues about referring to foreign law," she said. Scalia is the biggest critic of the practice, and Roberts and Alito are also opposed.

The court's citation of foreign laws in decisions that struck down laws prohibiting same-sex relations and in restricting the death penalty has prompted criticism and even led to a now-dormant move in Congress to prohibit the practice.

"There is perhaps a misunderstanding that when you refer to a decision of [foreign courts] that you are using those as binding precedent," she said.

But she added: "Why shouldn't we look to the wisdom of a judge from abroad with at least as much ease as we would read a law review article from a professor?"

She also said that the strides she made as an American Civil Liberties Union lawyer crusading for gender and pay equality and her work on the court have been less about forcing change than making sure the law reflects the change that society has sanctioned.

The court ended school segregation in Brown v. Board of Education, Ginsburg said, because the federal government said, "Please, court, help us."

The same was true, she said, about perhaps the most famous decision Ginsburg has written for the court and the one discussed most often on Friday: U.S. v. Virginia, which ended the men-only policy at Virginia Military Institute.

"Who brought the challenge to VMI?" she reminded. "Not some liberal group out there but the U.S. government."